This proposal seeks funds to purchase instrumentation that will allow the Case Western Reserve Cancer Center Gene Expression Array Core Facility [GEACF] to maintain state-of-the art services for its research community, while simultaneously addressing rapidly increasing demands for high sample number throughput and data reduction. To accomplish this aim, this proposal requests funds for an instrument package to be added to the existing Case Western Reserve University [CWRU] Core Facility and will provide the following: a) A new Affymetrix GeneChip Microarray Scanner System to allow experimental access to the new generation of gene expression microarrays; b) A system to improve the assessment of sample quality to facilitate the utilization of samples from translational studies and c) A state-of-the-art data management package tailored to address the data management needs of moderate to high-throughput laboratories. The ability to assess gene expression using microarrays is an essential resource in modern biomedical research. The Cancer Center at CWRU and University Hospitals of Cleveland [UHC] established the GEACF in January 2000, to make this technology available to their scientific investigators. The full service Affymetrix technology-based GEACF offers technical assistance and advice on all aspects of gene-expression technology. Over the past 3 years, the GEACF has rapidly grown from a Core Facility established to address the needs of Cancer Center investigators to a Facility that processes samples for CWRU, its Medical School and its affiliated institutions [UHHS, MetroHealth and The V.A. Hospital] as well as for the research faculty of the Cleveland Clinic Foundation. The GEACF supports diverse research by processing samples harvested from tissue culture, animals and people. Species currently emphasized include yeast, mouse, rat and human. The Core Facility currently supports the research efforts of 79 principal investigators. However, over the next 2 years we anticipate a significant expansion of our User base. In this regard, the CWRU Medical School is completing a large building project over the coming year, which will bring on-line more than 222,000 sq. ft. of additional laboratory space. The GEACF Facility will play a significant role in providing research infrastructure for researchers recruited to this new facility and investigators using its animal resources center that will house more than 70,000 mice.